1. Field of the Invention
The present invention relates to electrical power generation, and in particular to devices and methods for converting the gas pressure generated by explosives into electricity.
2. Description of the Prior Art
Useful electrical energy does not exist in nature and it must be converted from other available energy forms such as gasoline, diesel, coal, natural gas, geothermal, steam, hydro, solar, etc. Some of these energy sources are expensive, some are highly pollutant, some are difficult to convert efficiently, and some are not very portable as is needed in vehicles.
Explosives like gunpowder; Cordite, Ballistite, and Poudre-B smokeless powders; trinitrotoluene (TNT), Dynamite; nitroglycerin; Tovex and other water gel explosives; etc., release a lot of energy in a very rapid pulse. Explosives usually have less potential energy than petroleum fuels, but their high rate of energy release produces large blast pressures. TNT has a detonation velocity of 6,940 m/s compared to 1,680 m/s for the detonation of a pentane-air mixture, and the 0.34-m/s stoichiometric flame speed of gasoline combustion in air. Explosives are classified as “low” or “high” explosives according to their rates of decomposition. Gunpowder is a low explosive, while TNT is a high explosive. Low explosives burn rapidly or deflagrate, while high explosives detonate.
The energy released includes high levels of heat, light, and gas pressure. These are all quickly dissipated if not captured or otherwise contained. For example, at 15° C. the volume of gas produced by the explosive decomposition of one mole of nitroglycerin, becomes, V=(23.64 liter/mol)(7.25 mol)=171.4 liters. The molar volume of an ideal gas at 15° C. is about 23.64 liters. The potential of an explosive is the total work that can be performed by the gas generated by the explosion. If uncontained, it expands adiabatically from its original volume until its pressure is reduced to atmospheric pressure and its temperature to ambient.
In the nitroglycerin reaction, C3H5(NO3)3→3CO2+2.5H2O+1.5N2+0.25O2, the products are carbon dioxide, water, nitrogen, oxygen, and heat. Therefore, a relatively small solid or liquid volume is converted into a very large volume of relatively benign gases. Nitroglycerin explosions are relatively clean, compared to TNT which is poisonous and produces a lot of carbon soot in its reaction.
Firearms and artillery use the gas pressure generated by the detonation of smokeless powder to accelerate bullets and projectiles to very high muzzle velocities on the order of 2,000+ feet per second. Sticks of explosives are detonated in holes drilled into geologic deposits to fracture the ores and make removing the material as easy as scooping up the pieces.
What is needed is a device and method to convert explosive energy into a more useful form of electrical energy as used in homes and industry.